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November 1st, 2011, 12:41 PM   #1
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Finding k so that a given quadratic has real roots.

I need help with these questions. Any help would be greatly appreciated. Thanks.

1. Find the values of k such that the roots of x-k(x-1)(x-2)=0 are real roots.
[color=#FFFFFF]
2. A mural is to be painted on a wall that is 15 meters long an 12 meters high. A border of uniform width is to surround the mural. If the mural is to cover 75% of the area of the wall, how wide must the border be, to the nearest hundredth of a meter?

3. Write the reciprocal of a+bi in the simplest form.

4. Write a quadratic equation whose roots are 3+2i/2 and 3-2i/2.

5. For the following relation, determine the value of y in terms of x.
4x^2 - 4xy + y^2 - 2x + y - 6 = 0[/color]
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November 1st, 2011, 12:44 PM   #2
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Re: Help Please :)

1. Get this equation in standard form:


a, b, and c will be in terms of integers and "k".
The root(s) of this equation will be real when
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November 1st, 2011, 12:51 PM   #3
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Re: Help Please :)

Quote:
Originally Posted by The Chaz
1. Get this equation in standard form:


a, b, and c will be in terms of integers and "k".
The root(s) of this equation will be real when
I'm left with this: x-k.

I don't know what to do with the x-k.
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November 1st, 2011, 12:54 PM   #4
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Re: Help Please :)



If you're confused, then I'm concerned! Multiply...



Group the x's together...




Can you take it from here?
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November 1st, 2011, 01:09 PM   #5
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Re: Help Please :)

Quote:
Originally Posted by The Chaz


If you're confused, then I'm concerned! Multiply...



Group the x's together...




Can you take it from here?
Thanks, I was confused for some reason.

Can you help me solve the others?
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November 1st, 2011, 01:20 PM   #6
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Re: Help Please :)

Quote:
Originally Posted by tmac20
...

Thanks, I was confused for some reason.

Can you help me solve the others?
Yes, but let's do it this way:
Create a separate thread for each, so we can give them each an appropriate title and organize the replies.

I'll lock this thread so you can get started on that.
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November 1st, 2011, 01:29 PM   #7
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Re: Help Please :)

3.) The reciprocal or multiplicative inverse of a + bi is:



4.) We may write:









5.) We are given:



Write as quadratic on y:













edit: oops! I will move the responses to the appropriate threads once created!
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